Sentinel lymph node biopsy and risk factors for predicting metastasis in cutaneous squamous cell carcinoma.

BACKGROUND: Cutaneous squamous cell carcinoma (cSCC) is a common cancer capable of metastasis. Sentinel lymph node biopsy (SLNB) may be a valuable adjunct for patients with cSCC at high risk for metastasis. However, data on risk factors for metastasis and results of SLNB from patients with cSCC are limited.

OBJECTIVES: To evaluate risk factors for metastasis in patients with cSCC in a large cohort study with long-term follow-up and to determine the value of SLNB.

METHODS: We retrospectively analysed all records of patients who underwent excision of cSCC between January 2005 and August 2009 at a tertiary referral centre. In total, 143 patients were included in the cohort, including 17 patients with SLNB and a follow-up time of ≥ 24 months.

RESULTS: Tumour thickness > 4 mm and recurrent cSCC were strongly associated with metastatic disease. All metastases in this cohort occurred within 24 months of follow-up. SLNB showed a low sensitivity with regard to the development of metastasis. Six of 17 patients developed metastatic disease despite a negative SLNB.

CONCLUSIONS: Patients with risk factors (cSCC with a tumour thickness > 4 mm or recurrent disease) may develop metastases within the first 2 years despite a negative SLNB. Therefore these patients should be closely monitored during the follow-up. Based on our data SLNB does not provide diagnostic value for patients with cSCC.